But speaking the truth in love
through this man is preached unto you the forgiveness of sins
In Christ..
You can't possibly know if there is any truth from oral communication outside of the Scriptures, or if it even came from God if you didn't get it from the Holy, preserved, written words of God...
1Th 5:21 Prove all things; hold fast that which is good.
In order to prove all things, one must have the standard of proof from which things can be tested...
On the one side of the scale we have the preserved written words of God...On the other side we have human sinners who claim their 'truth' is authoritative and yet have no record of any source of their 'truth' except other sinful men...
Why would any Christian chose the word of men over the word of God??? I don't believe it's possible...
1Th 5:27 I charge you by the Lord that this epistle be read unto all the holy brethren.